skt_prepare: Prepare NWP Skin surface Temperature (SKT) data
In PCM: Cloud and snow discrimination on AVHRR imagery

Description Usage Arguments Value Note Author(s) References See Also Examples

View source: R/skt_prepare.R

This function remaps and interpolates (bilinear) to desired projection and geographic extent Skin surface Temperature data originating from the NWP model. Moreover the temperature correction provided by the dem_prepare function is added to the final results in order to improve temperature estimates over mountainous regions.

skt_prepare(NWP.skt.file = NWP.skt.file, out.dir = out.dir, out.proj = out.proj, out.extent = out.extent, out.dim = out.dim, correction.file = correction.file, NWP.skt.proj = NWP.skt.proj, NWP.skt.extent = NWP.skt.extent, NWP.skt.half.cell = NWP.skt.half.cell, NWP.skt.scale = NWP.skt.scale, NWP.skt.offset = NWP.skt.offset, NWP.skt.band = NWP.skt.band)

`NWP.skt.file`	Required! String with an absolute path to Numerical Weather Prediction Skin surface Temperature file. In can be stored in the .grib version 1 or 2 format but it has to be readable by `readGDAL`. If the input file consists of multiple bands please specify NWP.skt.band.
`out.dir`	Required! Output directory where the NWP_skt.tif file will be stored.
`out.proj`	Required! String with the Proj4 library coordinate system definition for the output file. To retrieve it type gdalinfo -proj4 your_file in the command line.
`out.extent`	Required! Numeric vector with the coordinates of the CENTRE of upper-left pixel and the CENTRE of lower-right pixel in a form c(ULX,ULY,LRX,LRY).
`out.dim`	Required! Numeric vector with the output dimensions in the form c(ncols,nrows).
`correction.file`	Required! String with an absolute path to the NWP_correction.tif file generated by the `dem_prepare` function.
`NWP.skt.proj`	Optional. String with the Proj4 library coordinate system definition for the NWP.skt.file. This overwrites the information which is retrieved by the `readGDAL`.
`NWP.skt.extent`	Optional. Numeric vector with the coordinates of the CENTRE of upper-left pixel and the CENTRE of lower-right pixel in a form c(ULX,YLY,LRX,LRY) for the NWP.skt.file. This overwrites the information which is retrieved by the `readGDAL`.
`NWP.skt.half.cell`	Optional. Numeric vector with the tie point of upper-left pixel in the NWP.skt.file. By default c(0,1). For further details see `readGDAL`.
`NWP.skt.scale`	Optional. Numeric value with a scale factor which is applied to skt data.
`NWP.skt.offset`	Optional. Numeric value with an offset which is applied to skt data.
`NWP.skt.band`	Optional. The number of the skt layer in the multiband NWP.skt.file. By default 1.

0 on success or 1 on failure. Success indicates that the output NWP_skt.tif file in the GeoTiff format was written to out.dir.

If you find one of the provided functions of this package useful please cite!

Jan Musial

Musial, J., Probabilistic approach to cloud and snow detection on AVHHR imagery, Atmos. Chem. Phys (in prep.)

PCM,dem_prepare

## Not run: 
skt_prepare(NWP.skt.file='/path/to/skt_file',
out.dir='/path/to/outdir/',
out.proj="+proj=laea +a=6370997.0 +b=6370997.0 +lat_0=50.0 +lon_0=20.0",
out.extent=c(-2521000.0,2401000.0,980000.0,-2000000.0),
out.dim=c(3500,4400),
correction.file='/path/to/NWP_correction.tif')

## End(Not run)